1 /* 2 * Copyright (c) 1997, 2018, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_CODE_CODECACHE_HPP 26 #define SHARE_VM_CODE_CODECACHE_HPP 27 28 #include "code/codeBlob.hpp" 29 #include "code/nmethod.hpp" 30 #include "gc/shared/gcBehaviours.hpp" 31 #include "memory/allocation.hpp" 32 #include "memory/heap.hpp" 33 #include "oops/instanceKlass.hpp" 34 #include "oops/oopsHierarchy.hpp" 35 #include "runtime/mutexLocker.hpp" 36 37 // The CodeCache implements the code cache for various pieces of generated 38 // code, e.g., compiled java methods, runtime stubs, transition frames, etc. 39 // The entries in the CodeCache are all CodeBlob's. 40 41 // -- Implementation -- 42 // The CodeCache consists of one or more CodeHeaps, each of which contains 43 // CodeBlobs of a specific CodeBlobType. Currently heaps for the following 44 // types are available: 45 // - Non-nmethods: Non-nmethods like Buffers, Adapters and Runtime Stubs 46 // - Profiled nmethods: nmethods that are profiled, i.e., those 47 // executed at level 2 or 3 48 // - Non-Profiled nmethods: nmethods that are not profiled, i.e., those 49 // executed at level 1 or 4 and native methods 50 // - All: Used for code of all types if code cache segmentation is disabled. 51 // 52 // In the rare case of the non-nmethod code heap getting full, non-nmethod code 53 // will be stored in the non-profiled code heap as a fallback solution. 54 // 55 // Depending on the availability of compilers and TieredCompilation there 56 // may be fewer heaps. The size of the code heaps depends on the values of 57 // ReservedCodeCacheSize, NonProfiledCodeHeapSize and ProfiledCodeHeapSize 58 // (see CodeCache::heap_available(..) and CodeCache::initialize_heaps(..) 59 // for details). 60 // 61 // Code cache segmentation is controlled by the flag SegmentedCodeCache. 62 // If turned off, all code types are stored in a single code heap. By default 63 // code cache segmentation is turned on if TieredCompilation is enabled and 64 // ReservedCodeCacheSize >= 240 MB. 65 // 66 // All methods of the CodeCache accepting a CodeBlobType only apply to 67 // CodeBlobs of the given type. For example, iteration over the 68 // CodeBlobs of a specific type can be done by using CodeCache::first_blob(..) 69 // and CodeCache::next_blob(..) and providing the corresponding CodeBlobType. 70 // 71 // IMPORTANT: If you add new CodeHeaps to the code cache or change the 72 // existing ones, make sure to adapt the dtrace scripts (jhelper.d) for 73 // Solaris and BSD. 74 75 class ExceptionCache; 76 class KlassDepChange; 77 class OopClosure; 78 class ShenandoahParallelCodeHeapIterator; 79 80 class CodeCache : AllStatic { 81 friend class VMStructs; 82 friend class JVMCIVMStructs; 83 template <class T, class Filter> friend class CodeBlobIterator; 84 friend class WhiteBox; 85 friend class CodeCacheLoader; 86 friend class ShenandoahParallelCodeHeapIterator; 87 private: 88 // CodeHeaps of the cache 89 static GrowableArray<CodeHeap*>* _heaps; 90 static GrowableArray<CodeHeap*>* _compiled_heaps; 91 static GrowableArray<CodeHeap*>* _nmethod_heaps; 92 static GrowableArray<CodeHeap*>* _allocable_heaps; 93 94 static address _low_bound; // Lower bound of CodeHeap addresses 95 static address _high_bound; // Upper bound of CodeHeap addresses 96 static int _number_of_nmethods_with_dependencies; // Total number of nmethods with dependencies 97 static nmethod* _scavenge_root_nmethods; // linked via nm->scavenge_root_link() 98 static uint8_t _unloading_cycle; // Global state for recognizing old nmethods that need to be unloaded 99 100 static ExceptionCache* volatile _exception_cache_purge_list; 101 102 static void mark_scavenge_root_nmethods() PRODUCT_RETURN; 103 static void verify_perm_nmethods(CodeBlobClosure* f_or_null) PRODUCT_RETURN; 104 105 // CodeHeap management 106 static void initialize_heaps(); // Initializes the CodeHeaps 107 // Check the code heap sizes set by the user via command line 108 static void check_heap_sizes(size_t non_nmethod_size, size_t profiled_size, size_t non_profiled_size, size_t cache_size, bool all_set); 109 // Creates a new heap with the given name and size, containing CodeBlobs of the given type 110 static void add_heap(ReservedSpace rs, const char* name, int code_blob_type); 111 static CodeHeap* get_code_heap_containing(void* p); // Returns the CodeHeap containing the given pointer, or NULL 112 static CodeHeap* get_code_heap(const CodeBlob* cb); // Returns the CodeHeap for the given CodeBlob 113 static CodeHeap* get_code_heap(int code_blob_type); // Returns the CodeHeap for the given CodeBlobType 114 // Returns the name of the VM option to set the size of the corresponding CodeHeap 115 static const char* get_code_heap_flag_name(int code_blob_type); 116 static size_t page_size(bool aligned = true); // Returns the page size used by the CodeCache 117 static ReservedCodeSpace reserve_heap_memory(size_t size); // Reserves one continuous chunk of memory for the CodeHeaps 118 119 // Iteration 120 static CodeBlob* first_blob(CodeHeap* heap); // Returns the first CodeBlob on the given CodeHeap 121 static CodeBlob* first_blob(int code_blob_type); // Returns the first CodeBlob of the given type 122 static CodeBlob* next_blob(CodeHeap* heap, CodeBlob* cb); // Returns the next CodeBlob on the given CodeHeap 123 124 static size_t bytes_allocated_in_freelists(); 125 static int allocated_segments(); 126 static size_t freelists_length(); 127 128 static void set_scavenge_root_nmethods(nmethod* nm) { _scavenge_root_nmethods = nm; } 129 static void prune_scavenge_root_nmethods(); 130 static void unlink_scavenge_root_nmethod(nmethod* nm, nmethod* prev); 131 132 // Make private to prevent unsafe calls. Not all CodeBlob*'s are embedded in a CodeHeap. 133 static bool contains(CodeBlob *p) { fatal("don't call me!"); return false; } 134 135 public: 136 // Initialization 137 static void initialize(); 138 139 static int code_heap_compare(CodeHeap* const &lhs, CodeHeap* const &rhs); 140 141 static void add_heap(CodeHeap* heap); 142 static const GrowableArray<CodeHeap*>* heaps() { return _heaps; } 143 static const GrowableArray<CodeHeap*>* compiled_heaps() { return _compiled_heaps; } 144 static const GrowableArray<CodeHeap*>* nmethod_heaps() { return _nmethod_heaps; } 145 146 // Allocation/administration 147 static CodeBlob* allocate(int size, int code_blob_type, int orig_code_blob_type = CodeBlobType::All); // allocates a new CodeBlob 148 static void commit(CodeBlob* cb); // called when the allocated CodeBlob has been filled 149 static int alignment_unit(); // guaranteed alignment of all CodeBlobs 150 static int alignment_offset(); // guaranteed offset of first CodeBlob byte within alignment unit (i.e., allocation header) 151 static void free(CodeBlob* cb); // frees a CodeBlob 152 static void free_unused_tail(CodeBlob* cb, size_t used); // frees the unused tail of a CodeBlob (only used by TemplateInterpreter::initialize()) 153 static bool contains(void *p); // returns whether p is included 154 static bool contains(nmethod* nm); // returns whether nm is included 155 static void blobs_do(void f(CodeBlob* cb)); // iterates over all CodeBlobs 156 static void blobs_do(CodeBlobClosure* f); // iterates over all CodeBlobs 157 static void nmethods_do(void f(nmethod* nm)); // iterates over all nmethods 158 static void metadata_do(void f(Metadata* m)); // iterates over metadata in alive nmethods 159 160 // Lookup 161 static CodeBlob* find_blob(void* start); // Returns the CodeBlob containing the given address 162 static CodeBlob* find_blob_unsafe(void* start); // Same as find_blob but does not fail if looking up a zombie method 163 static nmethod* find_nmethod(void* start); // Returns the nmethod containing the given address 164 static CompiledMethod* find_compiled(void* start); 165 166 static int blob_count(); // Returns the total number of CodeBlobs in the cache 167 static int blob_count(int code_blob_type); 168 static int adapter_count(); // Returns the total number of Adapters in the cache 169 static int adapter_count(int code_blob_type); 170 static int nmethod_count(); // Returns the total number of nmethods in the cache 171 static int nmethod_count(int code_blob_type); 172 173 // GC support 174 static void gc_epilogue(); 175 static void gc_prologue(); 176 static void verify_oops(); 177 // If any oops are not marked this method unloads (i.e., breaks root links 178 // to) any unmarked codeBlobs in the cache. Sets "marked_for_unloading" 179 // to "true" iff some code got unloaded. 180 // "unloading_occurred" controls whether metadata should be cleaned because of class unloading. 181 class UnloadingScope: StackObj { 182 ClosureIsUnloadingBehaviour _is_unloading_behaviour; 183 184 public: 185 UnloadingScope(BoolObjectClosure* is_alive) 186 : _is_unloading_behaviour(is_alive) 187 { 188 IsUnloadingBehaviour::set_current(&_is_unloading_behaviour); 189 increment_unloading_cycle(); 190 } 191 192 ~UnloadingScope() { 193 IsUnloadingBehaviour::set_current(NULL); 194 } 195 }; 196 static void do_unloading(BoolObjectClosure* is_alive, bool unloading_occurred); 197 static uint8_t unloading_cycle() { return _unloading_cycle; } 198 static void increment_unloading_cycle(); 199 static void asserted_non_scavengable_nmethods_do(CodeBlobClosure* f = NULL) PRODUCT_RETURN; 200 static void release_exception_cache(ExceptionCache* entry); 201 static void purge_exception_caches(); 202 203 // Apply f to every live code blob in scavengable nmethods. Prune nmethods 204 // from the list of scavengable nmethods if f->fix_relocations() and a nmethod 205 // no longer has scavengable oops. If f->fix_relocations(), then f must copy 206 // objects to their new location immediately to avoid fixing nmethods on the 207 // basis of the old object locations. 208 static void scavenge_root_nmethods_do(CodeBlobToOopClosure* f); 209 210 static nmethod* scavenge_root_nmethods() { return _scavenge_root_nmethods; } 211 // register_scavenge_root_nmethod() conditionally adds the nmethod to the list 212 // if it is not already on the list and has a scavengeable root 213 static void register_scavenge_root_nmethod(nmethod* nm); 214 static void verify_scavenge_root_nmethod(nmethod* nm); 215 static void add_scavenge_root_nmethod(nmethod* nm); 216 static void drop_scavenge_root_nmethod(nmethod* nm); 217 218 // Printing/debugging 219 static void print(); // prints summary 220 static void print_internals(); 221 static void print_memory_overhead(); 222 static void verify(); // verifies the code cache 223 static void print_trace(const char* event, CodeBlob* cb, int size = 0) PRODUCT_RETURN; 224 static void print_summary(outputStream* st, bool detailed = true); // Prints a summary of the code cache usage 225 static void log_state(outputStream* st); 226 static const char* get_code_heap_name(int code_blob_type) { return (heap_available(code_blob_type) ? get_code_heap(code_blob_type)->name() : "Unused"); } 227 static void report_codemem_full(int code_blob_type, bool print); 228 229 // Dcmd (Diagnostic commands) 230 static void print_codelist(outputStream* st); 231 static void print_layout(outputStream* st); 232 233 // The full limits of the codeCache 234 static address low_bound() { return _low_bound; } 235 static address low_bound(int code_blob_type); 236 static address high_bound() { return _high_bound; } 237 static address high_bound(int code_blob_type); 238 239 // Have to use far call instructions to call this pc. 240 static bool is_far_target(address pc); 241 242 // Profiling 243 static size_t capacity(); 244 static size_t unallocated_capacity(int code_blob_type); 245 static size_t unallocated_capacity(); 246 static size_t max_capacity(); 247 248 static double reverse_free_ratio(int code_blob_type); 249 250 static void clear_inline_caches(); // clear all inline caches 251 static void cleanup_inline_caches(); // clean unloaded/zombie nmethods from inline caches 252 253 // Returns true if an own CodeHeap for the given CodeBlobType is available 254 static bool heap_available(int code_blob_type); 255 256 // Returns the CodeBlobType for the given CompiledMethod 257 static int get_code_blob_type(CompiledMethod* cm) { 258 return get_code_heap(cm)->code_blob_type(); 259 } 260 261 static bool code_blob_type_accepts_compiled(int type) { 262 bool result = type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled; 263 AOT_ONLY( result = result || type == CodeBlobType::AOT; ) 264 return result; 265 } 266 267 static bool code_blob_type_accepts_nmethod(int type) { 268 return type == CodeBlobType::All || type <= CodeBlobType::MethodProfiled; 269 } 270 271 static bool code_blob_type_accepts_allocable(int type) { 272 return type <= CodeBlobType::All; 273 } 274 275 276 // Returns the CodeBlobType for the given compilation level 277 static int get_code_blob_type(int comp_level) { 278 if (comp_level == CompLevel_none || 279 comp_level == CompLevel_simple || 280 comp_level == CompLevel_full_optimization) { 281 // Non profiled methods 282 return CodeBlobType::MethodNonProfiled; 283 } else if (comp_level == CompLevel_limited_profile || 284 comp_level == CompLevel_full_profile) { 285 // Profiled methods 286 return CodeBlobType::MethodProfiled; 287 } 288 ShouldNotReachHere(); 289 return 0; 290 } 291 292 static void verify_clean_inline_caches(); 293 static void verify_icholder_relocations(); 294 295 // Deoptimization 296 private: 297 static int mark_for_deoptimization(KlassDepChange& changes); 298 #ifdef HOTSWAP 299 static int mark_for_evol_deoptimization(InstanceKlass* dependee); 300 #endif // HOTSWAP 301 302 public: 303 static void mark_all_nmethods_for_deoptimization(); 304 static int mark_for_deoptimization(Method* dependee); 305 static void make_marked_nmethods_not_entrant(); 306 307 // Flushing and deoptimization 308 static void flush_dependents_on(InstanceKlass* dependee); 309 #ifdef HOTSWAP 310 // Flushing and deoptimization in case of evolution 311 static void flush_evol_dependents_on(InstanceKlass* dependee); 312 #endif // HOTSWAP 313 // Support for fullspeed debugging 314 static void flush_dependents_on_method(const methodHandle& dependee); 315 316 // tells how many nmethods have dependencies 317 static int number_of_nmethods_with_dependencies(); 318 319 static int get_codemem_full_count(int code_blob_type) { 320 CodeHeap* heap = get_code_heap(code_blob_type); 321 return (heap != NULL) ? heap->full_count() : 0; 322 } 323 324 // CodeHeap State Analytics. 325 // interface methods for CodeHeap printing, called by CompileBroker 326 static void aggregate(outputStream *out, const char* granularity); 327 static void discard(outputStream *out); 328 static void print_usedSpace(outputStream *out); 329 static void print_freeSpace(outputStream *out); 330 static void print_count(outputStream *out); 331 static void print_space(outputStream *out); 332 static void print_age(outputStream *out); 333 static void print_names(outputStream *out); 334 }; 335 336 337 // Iterator to iterate over nmethods in the CodeCache. 338 template <class T, class Filter> class CodeBlobIterator : public StackObj { 339 public: 340 enum LivenessFilter { all_blobs, only_alive, only_alive_and_not_unloading }; 341 342 private: 343 CodeBlob* _code_blob; // Current CodeBlob 344 GrowableArrayIterator<CodeHeap*> _heap; 345 GrowableArrayIterator<CodeHeap*> _end; 346 bool _only_alive; 347 bool _only_not_unloading; 348 349 public: 350 CodeBlobIterator(LivenessFilter filter, T* nm = NULL) 351 : _only_alive(filter == only_alive || filter == only_alive_and_not_unloading), 352 _only_not_unloading(filter == only_alive_and_not_unloading) 353 { 354 if (Filter::heaps() == NULL) { 355 return; 356 } 357 _heap = Filter::heaps()->begin(); 358 _end = Filter::heaps()->end(); 359 // If set to NULL, initialized by first call to next() 360 _code_blob = (CodeBlob*)nm; 361 if (nm != NULL) { 362 while(!(*_heap)->contains_blob(_code_blob)) { 363 ++_heap; 364 } 365 assert((*_heap)->contains_blob(_code_blob), "match not found"); 366 } 367 } 368 369 // Advance iterator to next blob 370 bool next() { 371 assert_locked_or_safepoint(CodeCache_lock); 372 373 for (;;) { 374 // Walk through heaps as required 375 if (!next_blob()) { 376 if (_heap == _end) { 377 return false; 378 } 379 ++_heap; 380 continue; 381 } 382 383 // Filter is_alive as required 384 if (_only_alive && !_code_blob->is_alive()) { 385 continue; 386 } 387 388 // Filter is_unloading as required 389 if (_only_not_unloading) { 390 CompiledMethod* cm = _code_blob->as_compiled_method_or_null(); 391 if (cm != NULL && cm->is_unloading()) { 392 continue; 393 } 394 } 395 396 return true; 397 } 398 } 399 400 bool end() const { return _code_blob == NULL; } 401 T* method() const { return (T*)_code_blob; } 402 403 private: 404 405 // Advance iterator to the next blob in the current code heap 406 bool next_blob() { 407 if (_heap == _end) { 408 return false; 409 } 410 CodeHeap *heap = *_heap; 411 // Get first method CodeBlob 412 if (_code_blob == NULL) { 413 _code_blob = CodeCache::first_blob(heap); 414 if (_code_blob == NULL) { 415 return false; 416 } else if (Filter::apply(_code_blob)) { 417 return true; 418 } 419 } 420 // Search for next method CodeBlob 421 _code_blob = CodeCache::next_blob(heap, _code_blob); 422 while (_code_blob != NULL && !Filter::apply(_code_blob)) { 423 _code_blob = CodeCache::next_blob(heap, _code_blob); 424 } 425 return _code_blob != NULL; 426 } 427 }; 428 429 430 struct CompiledMethodFilter { 431 static bool apply(CodeBlob* cb) { return cb->is_compiled(); } 432 static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::compiled_heaps(); } 433 }; 434 435 436 struct NMethodFilter { 437 static bool apply(CodeBlob* cb) { return cb->is_nmethod(); } 438 static const GrowableArray<CodeHeap*>* heaps() { return CodeCache::nmethod_heaps(); } 439 }; 440 441 typedef CodeBlobIterator<CompiledMethod, CompiledMethodFilter> CompiledMethodIterator; 442 typedef CodeBlobIterator<nmethod, NMethodFilter> NMethodIterator; 443 444 #endif // SHARE_VM_CODE_CODECACHE_HPP